Upgraded to 3.0.1 issues, excerpt text is not showing

Hello,
I’m not a coder and had the site built for me. Each time I upgrade WP, some of the style either renders funny or not at all.
For example with the latest upgrade the “Recent Post” column in my left side-bar no longer displays “excerpt” text. It did before, and now I just have a list of Post titles. Does any one know where I would look to edit a file or otherwise fix this?

Thanks for your generosity of advice.
Cheers,
Mishka